The biggest difference between new energy electric vehicles and traditional fuel vehicles is that they use power batteries as power drives. As an important link between battery packs, vehicle systems and motors, the importance of BMS is self-evident. Many new energy car companies treat battery management systems as their core technology. The most famous example is Tesla, which everyone is familiar with. In Tesla’s “three big pieces” of electric vehicles, the battery comes from Panasonic and the motor comes from a Taiwanese supplier. Only the battery management system is the core technology independently developed by Tesla. Most of the core intellectual property rights that Tesla applied for from 2008 to 2015 were related to the battery management system, which shows the importance of the battery management system to new energy vehicles.
The American lithium-ion battery management system is in the forefront of the world. In addition to the aforementioned Tesla, Aerovironment has developed the SmartGuard system (Long-Life Battery Using Intelligent Modular Control System). At the 2012 Los Angeles Auto Show, General Motors launched a new pure electric vehicle “Spark E”, which follows Volt’s battery management system solution. AC Propulsion has developed a high-performance battery management system “BatOpt”. Gregory of the United States used the Kalman filter method based on the converted Coulomb efficiency to estimate the SOC. The Villanova University of the United States and the United States Nano Corporation cooperated to study the prediction of the battery SOC based on fuzzy logic. Johnson Controls of the United States uses variable impedance components to determine whether the battery temperature exceeds a predetermined threshold, and monitors the battery temperature in real time.
Japan has also achieved good results in the research of lithium battery management systems. Since the 1990s, Japan’s Qingchuan Industrial Research Center has concentrated on researching lithium-ion battery management systems and has carried out practical application and promotion. Toyota began to conduct vigorous research on electric vehicles more than ten years ago, and focused on the technical research and development of BMS. Germany has also made some achievements in the research of lithium-ion batteries. Germany, represented by Electronic GmbH and Werner Retzlaff, designed the BADICHEO system and the BADICOACH system, and B.Hauck designed the BATTMAN system. The battery management system of Kaiserslautern University of Technology in Germany adopts a distributed structure. The main module completes the functions of the management system, and the auxiliary module is an independent equalizer with strong equalization ability. A.Jossen and V.Spath showed an optimal SOC and SOH algorithm.
German Preh company (Preh) specializes in the production of auto parts, the main air conditioning control system, driver control system and new energy vehicle battery control system. At present, Preh’s customers cover all high-end car manufacturers in the world, including BMW, Audi, Volkswagen, Rolls Royce, Lamborghini, etc. In March 2014, Preh announced the launch of its latest battery management system (Electronic Control Unit, ECU), which is mainly aimed at pure electric BMW i3 models. The battery management system is composed of the electronic control element Battery Management Unit (BMU) and Battery Supervising Sensor Unit (CSSU), all of which are provided by the German Preh auto parts supplier. The battery monitoring sensor unit (CSSU) of Bridgelux’s new battery management system will constantly monitor the voltage and temperature changes of each battery pack, and the measured data will be processed by the battery management unit (BMU).
Looking at the global BMS market, traditional auto parts manufacturers represented by Denso and Preh have seized the opportunity by virtue of their important position in the supply chain of automakers. The former, as Toyota’s most important component supplier, has successively provided battery management modules for Prius, Camry Hybrid and other models; the latter mainly provides battery management systems for BMW I series pure electric vehicles.
And battery manufacturers are not far behind. LGC has established cooperative relationships with GM, Ford, Volvo and many other companies to provide them with power battery packs and supporting BMS. Among vehicle companies, Tesla’s advanced BMS technology is an important factor that distinguishes it in the market.